This is a Ph.D. dissertation. Contents include: General introduction, Protein
sorting in the late Golgi of Saccharomyces cerevisiae does not require mannosylated
sphingolipids, Sphingolipid mannosylation in yeast requires Csg2p-dependent
manganese transport into the lumen of early secretory organelles, HOR7, a multicopy
suppressor of the Ca2+-induced growth defect in sphingolipid mannosyltransferase-deficient
yeast, Loss of the yeast trans-Golgi P-type ATPases Drs2p and Dnf3p disrupts
aminophospholipid asymmetry in Pma1p-containing secretory vesicles, Summarizing
discussion, Abbreviations.